A staffer for U.S. Rep. Chuck Fleischmann ended up with a damaged tire at a recent campaign event for opponent Scottie Mayfield, and officials said video evidence shows the culprit came from Mayfield's bus.

Mayfield is challenging Fleischmann in Tennessee's 3rd Congressional District Republican primary. Officials said surveillance cameras captured the incident at the Roane County Courthouse, where Mayfield brought his campaign bus tour early Tuesday.

A Kingston, Tenn., Police Department report indicates that a man "came from a tour bus," walked up to Fleischmann campaign manager Tyler Threadgill's 2005 Audi, knelt down near the left rear wheel and "[appeared] to be fooling with the wheel."

"It was found that the man did cut the tire stem causing the tire to go flat down the road," according to the report. "The man is caught on video, and it is being determined who he is. The man left the vehicle and entered the courthouse and was caught on video there as well."

Kingston Assistant Police Chief Gary Nelson said he saw the video and wrote the police report. He said Mayfield's bus was the only bus he saw in the courthouse footage.

Nelson would not identify the man or release courthouse video, citing an ongoing investigation.

The name "should be [released] sometime pretty soon," he said.

Threadgill and Jordan Powell, another Fleischmann campaign staffer, traveled to Roane County to monitor Mayfield's speech.

"It's unfortunate that this incident happened," Powell said. "We're just glad our campaign staff is safe and that no one was harmed."

Mayfield spokesman Joe Hendrix said no one on the bus had any involvement.

"I do not think that anyone from our camp on that bus did this," he said.

It's the second video incident to emerge in an increasingly competitive 3rd District campaign. A hidden-camera clip anonymously posted to YouTube last week showed Mayfield saying he must get elected to Congress before getting "too focused" on what he wants to do there.

Weston Wamp and Ron Bhalla also are running in the race's GOP primary.